It is well known that many wounds and surgical incisions are closed using surgical sutures of some sort. Sutures are also commonly used in many other surgical applications, such as to repair damaged or severed muscles, vessels, tissue etc. Typically, the suture is attached at one end to a needle, and the needle is drawn through the tissue to form one or more loops holding the tissue together, and subsequently tied off so that the tissue will remain drawn together. Known surgical sutures include both monofilament sutures and braided sutures. It is also known to create barbs in a monofilament suture in an effort to prevent slippage of the suture within the tissue, an example of which is described in U.S. Pat. No. 5,931,855. These monofilament barbed sutures have been used a variety of cosmetic procedures including brow and face-lifts.
Monofilament, barbed sutures, however, become increasingly prone to failure as the required holding strength needed for a particular procedure increases. Since barbed sutures are typically formed by making cuts or slits in the suture using a blade of some sort, the slits act as stress concentration points. In applications where a significant load is placed on the suture, i.e., heart valve repair or replacement procedures and orthopedic applications, a given barb may fail, or begin peeling away from the suture shaft. Once this occurs, due to the fibrous nature of the suture material the barb may be stripped off the suture shaft along a significant length of the suture causing catastrophic failure.
Monofilament sutures all require one or more knots to be tied to secure the suture in place. Knot tying is a labor-intensive, and may significantly contribute to the overall time of a surgical procedure. In addition, in some surgical procedures the existence of the knot itself may be disadvantageous. For example, in mitral valve replacement procedures, a sewing ring surrounds the new valve and is used to sew the valve in place within the valve annulus. A typical procedure may use up to 20 sutures and result in up to approximately 160 knot throws. In addition to being time consuming, this number of knots can adversely affect the profile of the ring, which can interfere with the valve function.
Thus, it would be desirable to provide a suture having an increased holding strength and/or reduces or eliminates the need for knot tying.